XWayland::Primary: Fix unused warnings

src/xwayland/primary.cpp

@@ -146,6 +146,9 @@ void Primary::doHandleXfixesNotify(xcb_xfixes_selection_notify_event_t *event)
 
 void Primary::x11OffersChanged(const QStringList &added, const QStringList &removed)
 {
+    Q_UNUSED(added)
+    Q_UNUSED(removed)
+
     m_waitingForTargets = false;
     X11Source *source = x11Source();
     if (!source) {